Antibiotics previously effective against pathogenic bacteria are rapidly being compromised by the spread of multiply resistant strains. In this Phase II program, Pinnacle Pharmaceuticals seeks to expand an assay system that has allowed the simultaneous identification of novel antibacterial compounds and of targets against which those compounds act. The Specific Aims of the present Phase II application are: 1. Specific Aim One: Purification and characterization of active principles derived from four target/inhibitor pairs elucidated in Phase I research. 2. Specific Aim Two: Target validation of the identified multicopy suppressing gene products using biochemical and bioinformatic approaches. 3. Specific Aim Three: Continued screening to identify new inhibitor/target pairs, resulting in characterized active principles for five of these new pairs.